Accession Number : AD0761215

Title :   Modification and Control of Oxide Structures on Metals and Alloys: (Phase III).

Descriptive Note : Final rept. 20 Dec 71-20 Jan 73,

Corporate Author : WESTINGHOUSE ELECTRIC CORP PITTSBURGH PA ASTRONUCLEAR LAB

Personal Author(s) : Svedberg,Robert C.

Report Date : FEB 1973

Pagination or Media Count : 198

Abstract : The rutile structure family for oxide compounds of the type Nb(B)O4 where B = Cr, Al, or Fe have been identified as being the primary oxide phase in the scales formed on oxidation resistant Nb intermetallic compounds and Nb-Ti-Cr-Al, Nb-Fe-Al, Nb-Cr-Al-Co, and Nb-Cr-Al-Ni alloys. Along with this oxide, small amounts of either (B)2O3 where B = Cr, Al, or Fe or a CoAl2O4 spinel in cobalt containing alloys were detected. Oxygen transport rates through Nb2O3-Cr2O3, Nb2O5-TiO2, Nb2O5-ZrO2, and Nb2O5-Al2O3 were also determined using thermogravimetric techniques. Of the oxide compounds evaluated, only oxygen transport through Nb2O5-Cr2O3 was slow enough to warrent its classification as a protective scale. In addition to oxidation rate data, metallographic studies and electron microprobe studies are reported for the Nb intermetallic compounds and alloys. (Author)

Descriptors :   (*REFRACTORY METAL ALLOYS, *CORROSION INHIBITION), (*OXYGEN, *DIFFUSION), (*OXIDES, DIFFUSION), OXIDATION, THERMOGRAVIMETRIC ANALYSIS, INTERMETALLIC COMPOUNDS, NIOBIUM ALLOYS, ZIRCONIUM OXIDES, ALUMINUM COMPOUNDS, ZIRCONIUM COMPOUNDS, TITANIUM COMPOUNDS, ALUMINUM ALLOYS, CHROMIUM ALLOYS, CHROMIUM COMPOUNDS, IRON ALLOYS, COBALT ALLOYS, NICKEL ALLOYS

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE